Mark J. Osiel

Aliber Family Chair in Law Emeritus

Mark Osiel's writings have inspired scholarly conferences and are assigned at many leading universities throughout the world, in a number of fields. His works seek to show how we may improve the law’s responses to mass atrocity by better understanding its organizational forms and social dynamics. His books include Mass Atrocity, Collective Memory & the Law (1997), Obeying Orders: Atrocity, Military Discipline, and the Law of War (1999), Mass Atrocity, Ordinary Evil, and Hannah Arendt: Criminal Consciousness in Argentina's Dirty War (Yale Univ. Press, 2002), Making Sense of Mass Atrocity (Cambridge Univ. Press, 2009), The End of Reciprocity: Terror, Torture & the Law of War (Cambridge Univ. Press, 2009); The Right to Do Wrong: A Social Scientific Look at Law’s Relation to Morality (Harvard Univ. Press, 2019). His articles have appeared in the Harvard Law ReviewColumbia Law ReviewCalifornia Law ReviewPennsylvania Law ReviewJournal of Legal AnalysisHuman Rights QuarterlyLaw & Social Inquiry, Ethics & International Affairs, Dissent, and Representations.

Professor Osiel has served as consultant in several, high-profile international trials and advised the Department of Defense on anti-terrorism prosecutions. He regularly addresses international organizations and governments in post-conflict societies on issues of transitional justice. He was Director for International Criminal and Humanitarian Law at the T.M.C. Asser Institute, in The Hague, and is an occasional media commentator on legal aspects of contemporary armed conflicts.

Osiel has been a visiting fellow at Cambridge University, Harvard's Kennedy School of Government, Stanford, the London School of Economics, the American Bar Foundation/Northwestern, as well as universities in Argentina, Brazil, France, The Netherlands, and India (as a Fulbright Lecturer). After accepting a clerkship on the US Court of Appeals for the Seventh Circuit, Prof. Osiel practiced civil litigation for two years at Foley Hoag, a Boston law firm. Before attending law school, he worked as a Head Start counselor and as a paramedic in Guatemala.

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Practice and Teaching: 

  • International Criminal/Humanitarian Law 
  • Judicial Remedies
  • International Law
  • Transitional Justice
  • The Law of Armed Conflict
Mark Osiel (1)
BA, University of California, Berkeley, 1977
MA, University of Chicago, 1978
JD, PhD, Harvard University, 1987